From a53c115888e2e3367c0298eb7639314e1eb31dc7 Mon Sep 17 00:00:00 2001
From: hongfaqiu <951142905@qq.com>
Date: Mon, 26 Jun 2023 18:05:13 +0800
Subject: [PATCH] perf: some uncertain modifications

---
 .../src/TIFFImageryProvider.ts                | 39 ++++++-------------
 .../TIFFImageryProvider/src/plotty/index.ts   | 18 ++++-----
 .../TIFFImageryProvider/src/plotty/typing.ts  |  2 +-
 .../TIFFImageryProvider/src/worker-farm.ts    |  2 +-
 4 files changed, 22 insertions(+), 39 deletions(-)

diff --git a/packages/TIFFImageryProvider/src/TIFFImageryProvider.ts b/packages/TIFFImageryProvider/src/TIFFImageryProvider.ts
index e76b5bc..f19b856 100644
--- a/packages/TIFFImageryProvider/src/TIFFImageryProvider.ts
+++ b/packages/TIFFImageryProvider/src/TIFFImageryProvider.ts
@@ -1,4 +1,4 @@
-import { Event, GeographicTilingScheme, Credit, Rectangle, ImageryLayerFeatureInfo, Math as CMath, DeveloperError, defined } from "cesium";
+import { Event, GeographicTilingScheme, Credit, Rectangle, ImageryLayerFeatureInfo, Math as CMath, DeveloperError, defined, ImageryProvider } from "cesium";
 import GeoTIFF, { Pool, fromUrl, fromBlob, GeoTIFFImage } from 'geotiff';
 
 import { addColorScale, plot } from './plotty'
@@ -132,7 +132,7 @@ function getWorkerPool() {
   return workerPool;
 }
 
-export class TIFFImageryProvider {
+export class TIFFImageryProvider extends ImageryProvider {
   ready: boolean;
   tilingScheme: GeographicTilingScheme;
   rectangle: Rectangle;
@@ -142,7 +142,7 @@ export class TIFFImageryProvider {
   maximumLevel: number;
   minimumLevel: number;
   credit: Credit;
-  private _error: Event;
+  errorEvent: Event;
   readyPromise: Promise<boolean>;
   private _destroyed = false;
   _source!: GeoTIFF;
@@ -150,7 +150,7 @@ export class TIFFImageryProvider {
   _images: (GeoTIFFImage | null)[] = [];
   _imagesCache: Record<string, {
     time: number;
-    data: ImageData | HTMLCanvasElement | HTMLImageElement;
+    data: ImageBitmap | HTMLCanvasElement | HTMLImageElement;
   }> = {};
   bands: Record<number, {
     min: number;
@@ -169,11 +169,12 @@ export class TIFFImageryProvider {
     /** Deprecated */
     url?: string | File | Blob;
   }) {
+    super();
     this.hasAlphaChannel = options.hasAlphaChannel ?? true;
     this.maximumLevel = options.maximumLevel ?? 18;
     this.minimumLevel = options.minimumLevel ?? 0;
     this.credit = new Credit(options.credit || "", false);
-    this._error = new Event();
+    this.errorEvent = new Event();
 
     this._workerFarm = new WorkerFarm();
     this._cacheTime = options.cache ?? 60 * 1000;
@@ -186,15 +187,6 @@ export class TIFFImageryProvider {
     }
   }
 
-  /**
-   * Gets an event that will be raised if an error is encountered during processing.
-   * @memberof GeoJsonDataSource.prototype
-   * @type {Event}
-   */
-  get errorEvent() {
-    return this._error
-  }
-
   get isDestroyed() {
     return this._destroyed
   }
@@ -361,7 +353,7 @@ export class TIFFImageryProvider {
       }
     } catch (e) {
       console.error(e);
-      this._error.raiseEvent(e);
+      this.errorEvent.raiseEvent(e);
     }
     this.readyPromise = Promise.resolve(true);
     this.ready = true;
@@ -456,7 +448,7 @@ export class TIFFImageryProvider {
         height: this.tileHeight
       };
     } catch(error) {
-      this._error.raiseEvent(error);
+      this.errorEvent.raiseEvent(error);
       throw error;
     }
   }
@@ -483,7 +475,7 @@ export class TIFFImageryProvider {
         return undefined;
       }
       
-      let result: ImageData | HTMLImageElement
+      let result: ImageBitmap | HTMLImageElement
       
       if (multi || convertToRGB) {
         const opts = {
@@ -520,16 +512,7 @@ export class TIFFImageryProvider {
         }
 
         const image = new Image();
-        if (this.plot.canvas instanceof HTMLCanvasElement) {
-          image.src = this.plot.canvas.toDataURL();
-        } else {
-          const imgBitmap = this.plot.canvas.transferToImageBitmap();
-          canvas.width = imgBitmap.width;
-          canvas.height = imgBitmap.height;
-          const ctx = canvas.getContext('2d');
-          ctx.drawImage(imgBitmap, 0, 0);
-          image.src = canvas.toDataURL();
-        }
+        image.src = this.plot.canvas.toDataURL();
         result = image;
       }
 
@@ -548,7 +531,7 @@ export class TIFFImageryProvider {
       return result;
     } catch (e) {
       console.error(e);
-      this._error.raiseEvent(e);
+      this.errorEvent.raiseEvent(e);
       throw e;
     }
   }
diff --git a/packages/TIFFImageryProvider/src/plotty/index.ts b/packages/TIFFImageryProvider/src/plotty/index.ts
index 4535eed..aa7e389 100644
--- a/packages/TIFFImageryProvider/src/plotty/index.ts
+++ b/packages/TIFFImageryProvider/src/plotty/index.ts
@@ -18,7 +18,7 @@ function hasOwnProperty(obj: any, prop: string) {
 
 function defaultFor(arg: any, val: any) { return typeof arg !== 'undefined' ? arg : val; }
 
-function create3DContext(canvas: HTMLCanvasElement | OffscreenCanvas, optAttribs: { premultipliedAlpha: boolean; }) {
+function create3DContext(canvas: HTMLCanvasElement, optAttribs: { premultipliedAlpha: boolean; }) {
   const names = ['webgl', 'experimental-webgl'];
   let context: WebGLRenderingContext | null= null;
   for (let ii = 0; ii < names.length; ++ii) {
@@ -251,13 +251,13 @@ void main() {
  *
  */
 class plot {
-  canvas: HTMLCanvasElement | OffscreenCanvas;
+  canvas: HTMLCanvasElement;
   currentDataset: DataSet;
   datasetCollection: Record<string, DataSet>;
   gl: WebGLRenderingContext | null;
   program: WebGLProgram;
   texCoordBuffer: WebGLBuffer;
-  ctx: OffscreenCanvasRenderingContext2D | CanvasRenderingContext2D;
+  ctx: CanvasRenderingContext2D;
   displayRange: number[];
   applyDisplayRange: boolean;
   matrix: number[];
@@ -282,8 +282,8 @@ class plot {
     if (defaultFor(options.useWebGL, true)) {
       // Try to create a webgl context in a temporary canvas to see if webgl and
       // required OES_texture_float is supported
-      if (create3DContext(new OffscreenCanvas(512, 512), {premultipliedAlpha: false}) !== null) {
-        const gl = create3DContext(this.canvas, {premultipliedAlpha: false});
+      const gl = create3DContext(this.canvas, { premultipliedAlpha: false });
+      if (gl !== null) {
         this.gl = gl;
         this.program = createProgram(gl, vertexShaderSource, fragmentShaderSource);
         gl.useProgram(this.program);
@@ -466,9 +466,9 @@ class plot {
   /**
    * Set the canvas to draw to. When no canvas is supplied, a new canvas element
    * is created.
-   * @param {HTMLCanvasElement | OffscreenCanvas} [canvas] the canvas element to render to.
+   * @param {HTMLCanvasElement} [canvas] the canvas element to render to.
    */
-  setCanvas(canvas: HTMLCanvasElement | OffscreenCanvas) {
+  setCanvas(canvas: HTMLCanvasElement) {
     this.canvas = canvas || document.createElement('canvas');
   }
 
@@ -503,9 +503,9 @@ class plot {
 
   /**
    * Get the canvas that is currently rendered to.
-   * @returns {HTMLCanvasElement | OffscreenCanvas} the canvas that is currently rendered to.
+   * @returns {HTMLCanvasElement} the canvas that is currently rendered to.
    */
-  getCanvas(): HTMLCanvasElement | OffscreenCanvas {
+  getCanvas(): HTMLCanvasElement {
     return this.canvas;
   }
 
diff --git a/packages/TIFFImageryProvider/src/plotty/typing.ts b/packages/TIFFImageryProvider/src/plotty/typing.ts
index 625fa46..56b1e4b 100644
--- a/packages/TIFFImageryProvider/src/plotty/typing.ts
+++ b/packages/TIFFImageryProvider/src/plotty/typing.ts
@@ -19,7 +19,7 @@ export type PlotOptions = {
   /**
    * The canvas to render to.
    */
-  canvas?: HTMLCanvasElement | OffscreenCanvas;
+  canvas?: HTMLCanvasElement;
 
   /**
    * The raster data to render.
diff --git a/packages/TIFFImageryProvider/src/worker-farm.ts b/packages/TIFFImageryProvider/src/worker-farm.ts
index 1b1a78f..75547ea 100644
--- a/packages/TIFFImageryProvider/src/worker-farm.ts
+++ b/packages/TIFFImageryProvider/src/worker-farm.ts
@@ -13,7 +13,7 @@ async function sendMessage(worker: Worker, payload: { data: TypedArray[], opts:
     id: msgId,
     payload,
   };
-  return new Promise<ImageData>(function (resolve, reject) {
+  return new Promise<ImageBitmap>(function (resolve, reject) {
     // save callbacks for later
     resolves[msgId] = resolve;
     rejects[msgId] = reject;